<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>bootstrap</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    <style>
    .fz div {
        font-size: 50px;
        background: cornflowerblue;
    }
    </style>
</head>
<body>
<div class="container-fluid">
    <div class="row fz ">  <!-- 行 -->
        <div class="col-lg-4">1</div>
        <div class="col-lg-4 col-lg-offset-4">2</div>
    </div>
</div>


<div class="container-fluid">
    <div class="row fz ">  <!-- 行 -->
        <div class="col-lg-4 col-lg-offset-4">A</div>
    </div>
</div>

<div class="container-fluid">
    <div class="row">
        <div class="col-sm-9">
            Level 1
          <div class="row">
            <div class="col-sm-6">Level 2</div>
            <div class="col-sm-6">Level 3</div>
          </div>
        </div>
        <div class="col-sm-3">Level AAAA</div>
    </div>
</div>


<div class="container-fluid fz">
    <div class="row">
        <div class="col-md-9 col-md-push-3">333333</div>
        <div class="col-md-3 col-md-pull-9">999999</div>
      </div>
</div>

</body>
</html>